Gaseous electric discharge device



GASEOUS ELECTRIC DISCHARGE DEVICE Filed Feb. 5, 1934 E INVENTOR 1 l I l l BY mmf ATTO NEY u y1,990,177Q` GAsEoUs ELECTRIC DISCHARGE DEVICEl Y. Y :"aHeimich Friedrichsen, BerlinTreptow, Germany;` l 1-, m" 1.', :aSslgnor to General Electricoinpany,acorpo-j ration of, New York Application February 5, 1934, Serial No. 709,876 In Germany February 22, 19.33

1 Claim.

The present invention relates to gaseous electric discharge devices generally and more rparticularly the invention relates to-such devices of the cathode glow type useful infelectrical circuits generally as a protection against over-voltage conditions. p

Cathode glow devices serveadmirably for this purpose due to the fact that these devices ,pass no current on voltages below theirbreak-down voltage, that is the voltage required to start the device into operation. Thebreakdown voltage of such devices depends on a numberv of factors, such as the electrode material, the spacing of the electrodes, and the electrical conducting characteristics of the gaseous iillingand the breakdown voltage of such devicesvis controlled by these various factors. It is the practice in the art to regulate the break-down voltage so that it is slightly greater than the voltage of the source. While the above enumerated factors make it possible to control the break-down voltage of the device to some extent the range over which it is possible to control the voltage is rather limited.

The object of the present invention is to provide a gaseous electric discharge device of the cathode glow type having a higher break-down voltage than similar devices now known in the art. Another object of the invention is to provide such a device of simple, compact and rugged structure. A further object of the invention is to provide a method of and a means for controlling the break-down voltagevof a cathode glow electric discharge device over a wide range of voltages. Still further objects and advantages attaching to the device and to its use and operation will be apparent to those skilled in the art from the following particular description.

In accordance with these objects the new and novel cathode glow gaseous electric discharge device comprises a tubular container and a plurality of disc shaped electrodes the largest diameter of which closely approaches the inner diameter of said container so that the space between the rim of said electrodes and said container is less than that necessary for gaseous conduction. Said electrodes are spaced apart on and secured to a rod of insulation material extending along the container. The electrode at either end of said container is provided with a current lead connected to a base attached to the end of said container. The electrodes between the end electrodes have no direct connection to the current source and the discharges between said electrodes are in series. The break-down potential (C1. Z50-27,5) l

of said device is thus equivalent to the total breakdown potential of the discharges between the pairs of electrodes. The break-down potential of the new and novel glow lamp can be controlled over a wide range by changing the number of the electrodes between the. end electrodes in said device.

In the drawing accompanying and forming part of thisspecification an embodiment of the in-y vention is shown in a sectional side elevational view.

Referring tothe drawing the new and novel cathode glow electric discharge device comprises a tubular container l having a plurality of disc shaped electrodes 2, 3, 4 and 5 of conducting material, such as iron, nickel, or aluminium, sealed therein. The outer rims of said electrodes 2, 3, 4 andv 5 are flanged so as to be flexible and .the diameter ofthe flanged part Vof each electrode closely approaches the inner diameter of the container 1. The distance between the anges of the electrodes and the inner wall of said con-` tainer 1 is less than the mean free path of an ionized gas particle to prevent the passage .of the discharge through the space between said electrodes and said container. A rod 6 of insulation material, such as magnesium oxide or aluminium oxide, extends through the central opening in each of said electrodes 2 to 5 and sleeves 7, 8 and 9 on said rod 6 andkinterposed between the electrodes maintain the electrodes in spacedrelation. Rings 10 and 11 at the ends y of said rod 6 prevent the electrodes moving along said rod 6. The end electrodes 2 and 5 are connected to the bases 16 and 17, cemented to either end of the container 1, by leads 12 and 13 sealed into the parts 14 and 15 respectively of said container l. Said electrodes 2 to 5 are supported by said rod 6 and said leads 12 and 13.

Saidcontainer l is iilled with a rare gas, such as neon, at a pressure of approximately 30 mm.

vThree series discharges take place in said device; one between said electrodes 2 and 3; another between said electrodes 3 and 4 and an other between said electrodes 4 and 5 when potential is applied across the terminals of the device; The break-down voltage of the device is three times that' of a similar device having but one discharge path therein and is approximately 500 to 600 volts. rlhis breakdown voltage cank be changed over a wide range by changing vthe number of electrodes between said electrodes 2 and 5.

While. I have shown and described and have pointed out in the annexed claim certain novel features of the invention, it will be understood that various omissions, substitutions and changes in the forms and details of the device illustrated and in its use and operation may be made by those skilled in the art without departing from the brd "spitintfail scope Bf the invention, -Ir example; an leletrh efnissiv'e i'nateiiai; v`as barium oxide, is applied to the discharge supporting surfaces of said electrodes 2, 3, 4` r'n'l'v 5, when desired. n' j What I claim as new and Adeife t scue'y Letters Patent of the United States A gaseous electric disch ie'ic of the cam-'i' ode glow type comprising a tubular container. a plurality of electrodes Vsealed therein, a gaseous atmosphere therein, said electrodes being metal discs each having a ilanged rim, said discs being transverse to the longitudinal axis of said container, the space between the rim of said electrodes` andthe inner wall of said container being less than tliatneceiryl'! ff 'onduction, a rbd tf imitating' wenn extending along the longitudinal axis of said container and th'ough said electrodes, a. sleeve of` insulating material on said rod interposed between said 'electrodes and" maintaining said e1ectrodes in `spaced relation in 'said container.

. `mgrNRIcH FRIEDRICHSEN. 

